Locksets are susceptible to various types of attacks. In many attacks, manipulation of the cylinder plug is critical to overcoming the lock. However, it is generally difficult to know whether the integrity of the cylinder has been compromised by an attack unless the lock is marred by forced entry. Even in situations with forced entry, there may be no visible indication that the cylinder has been compromised. Therefore, there is a need for a device that monitors integrity of lock cylinders.
According to one aspect, this disclosure provides a lock cylinder with a cylinder body and a cylinder plug disposed in the cylinder body. The cylinder plug includes a portion configured to deform and/or separate from the cylinder body when a sufficient force is applied to the cylinder plug. A sensor assembly is provided that detects when at least a portion of the cylinder body deforms and/or separates from the cylinder body. One skilled in the art should appreciate that numerous sensors could be used to detect separation of the cylinder plug with respect to the cylinder body and this disclosure is not intended to be limited to the example sensors described herein. By way of example only, the sensor assembly could detect when the cylinder plug deforms and/or separates from the cylinder plug with a strain gauge, a continuity circuit, a micro-switch, an optical sensor, accelerometer and/or a contact microphone. In some embodiments, the sensor assembly could include an opening dimensioned to receive the cylinder plug. For example, the sensor assembly could include a raised edge surrounding the opening. Depending on the circumstances, one or more sensors could be in the raised edged edge. In some cases, the opening in the sensor assembly may be coaxial with an opening in the cylinder body that receives the cylinder plug.
According to another aspect, this disclosure provides a lock cylinder with a cylinder body and a cylinder plug disposed in the cylinder body. The cylinder plug includes a portion configured to deform and/or separate from the cylinder body when a sufficient force is applied. The lock cylinder includes means for detecting when the cylinder plug deforms and/or separates from the cylinder body. Depending upon the circumstances, the means for detecting when at least a portion of the cylinder plug deforms and/or separates from the cylinder body could be one or more of a strain gauge, a continuity circuit, a micro-switch, an optical sensor, accelerometer and/or a contact microphone.
In yet another aspect, this disclosure provides a lockset with an exterior assembly and interior assembly. The exterior assembly includes a cylinder body and cylinder plug disposed in the cylinder body. The cylinder plug includes a portion configured to deform and/or separate from the cylinder body when a sufficient force is applied. The exterior assembly includes a sensor assembly configured to detect when the cylinder plug deforms and/or separates from the cylinder body. The interior assembly includes an interior driver operatively coupled to the cylinder plug with a torque blade extending therebetween. A circuit is electrically connected to the sensor assembly and controls movement of the interior driver. The interior assembly also includes a tamper lock operative to restrict movement of the interior driver. The circuit actuates the tamper lock responsive to detection by the sensor assembly that at least a portion of the cylinder plug has deformed and/or separated from the cylinder body. In some cases, the circuit signals an alarm responsive to detection by the sensor assembly that at least a portion of the cylinder plug has deformed and/or separated from the cylinder body. For example, the circuit could actuate an audible alarm with a speaker responsive to detection by the sensor assembly that at least a portion of the cylinder plug has deformed and/or separated from the cylinder body. In some embodiments, the circuit is configured to transmit a wireless message indicating that the sensor assembly has detected deformation and/or separation of the cylinder plug. Depending on the circumstances, the tamper lock could include a solenoid with a bolt movable between an extended and retracted position based on control by the circuit. In some cases, the bolt of the solenoid limits movement of the interior driver when the bolt is in the extended position.
In a further aspect, this disclosure provides a method of detecting tampering with a lock cylinder. The method includes the steps of providing a cylinder body and a cylinder plug disposed in the cylinder body. The cylinder plug includes a portion configured to deform and/or separate from the cylinder body when a sufficient force is applied. The method also includes the step of monitoring the cylinder plug to detect when at least a portion of the cylinder plug deforms and/or separates from the cylinder body. If the cylinder plug deforms and/or separates from the cylinder body, an electrical signal is generated indicating tampering of the cylinder plug. In some cases, an audible alarm is generated responsive to detection that at least a portion of the cylinder plug has deformed and/or separated from the cylinder body. Embodiments are contemplated in which a tamper lock that locks the cylinder plug is actuated responsive to detection that at least a portion of the cylinder plug has deformed and/or separated from the cylinder body.
Additional features and advantages of the disclosure will become apparent to those skilled in the art upon consideration of the following detailed descriptions exemplifying the best mode of carrying out the disclosure as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. The exemplification set out herein illustrates embodiments of the invention, and such exemplification is not to be construed as limiting the scope of the invention in any manner.